The only way to access it is by taking the Rainbow Stoneship from the Hidden Land. Additionally, the only Pokémon allowed to enter are the main player and their partner. Lapras will bring the player to Hidden Land, which must be completed before entering Temporal Tower.

Temporal Tower has a relay point after 13F. In the first visit the player will have to defeat Primal Dialga. After that, the player can recruit Dialga in its regular state.

Trivia

Like in the previous game, a tower is the final dungeon of the story mode. However, friend Pokémon cannot be taken to Temporal Tower, unlike Sky Tower.

At the relay point, Temporal Spire, and when at Temporal Pinnacle, one can hear a clock faintly ticking in the background: this and the location's name are likely due to the fact that Temporal Tower is the structure of time.

The Temporal Pinnacle, where Dialga is found, bears a striking resemblance to the Spear Pillar (where Dialga is also found).

The 24 floors of this dungeon may be a reference to the 24 hours of the day.

Only the player and partner can ever come to Temporal Tower. Ironically, that means that if Dialga is recruited by the player, the only way it can return to Temporal Tower is if it is released.

Despite being the last dungeon in the storyline, its layouts are simpler than those of the previous dungeon, Hidden Land.